Structural components in an aircraft can be made of honeycomb core that includes multiple open adjoining cells. For example, a blade in a rotorcraft can use honeycomb core internally to provide rigidity and strength to the blade. The open structure of each cell in a honeycomb core can provide structural support while reducing weight. Honeycomb core can be made from different materials including polymers, fibers, paper, or combinations of materials. In some cases, the size of a honeycomb core is limited by the size allowed by the manufacturing process.